Remove GetVolume from media::AudioRendererSink.

media/base/audio_renderer_mixer_input.h

Index: media/base/audio_renderer_mixer_input.h
diff --git a/media/base/audio_renderer_mixer_input.h b/media/base/audio_renderer_mixer_input.h
index 7e8c9f1ccd6896fcf337048188caa7d02ae22f1e..c240ec50c650d908f2e36d840bdece8a70382dd9 100644
--- a/media/base/audio_renderer_mixer_input.h
+++ b/media/base/audio_renderer_mixer_input.h
@@ -31,10 +31,11 @@ class MEDIA_EXPORT AudioRendererMixerInput
   virtual void Play() OVERRIDE;
   virtual void Pause(bool flush) OVERRIDE;
   virtual bool SetVolume(double volume) OVERRIDE;
-  virtual void GetVolume(double* volume) OVERRIDE;
   virtual void Initialize(const AudioParameters& params,
                           AudioRendererSink::RenderCallback* renderer) OVERRIDE;
 
+  void GetVolume(double* volume);
+
  protected:
   virtual ~AudioRendererMixerInput();